1. Field of the Invention
The present invention is related to a screening method to identify compounds that impact taste. More specifically, the present invention relates to a screening method useful in the identification of compounds that affect taste sensation by modulating the level of activation of the ion channel TRPA1. The screening method allows for the rapid screening of candidate compounds by providing a visual fluorescent readout that can be easily automated.
2. Background
Taste perception plays a critical role in the nutritional status and survival of both lower and higher animals (Margolskee, R. F. J. Biol. Chem. 277:1-4 (2002); Avenet, P. and Lindemann, B. J. Membrane Biol. 112:1-8 (1989)). The ability to taste has significance beyond providing people with pleasurable culinary experiences. For example, the ability to taste allows us to identify tainted or spoiled foods, and provides satisfying responses that may be proportionate to caloric or nutritive value.
Although taste perception is a vital function, sometimes it is useful to modify certain tastes. For example, many active ingredients in medicines produce undesirable tastes, such as a bitter taste or a pungent burning sensation. Inhibition of this bitter taste or burning sensation could lead to improved acceptance by the patient. In other circumstances, it may be desirable to enhance the unpleasant taste of something that would be toxic if ingested. For instance, an increased bitterness or burning quality could prevent consumption of poisonous materials that ordinarily have little or no taste. For example, denatonium benzoate, a highly bitter compound is added to methanol and other poisonous liquids to discourage their ingestion.
Thymol, an antibacterial that is the active ingredient in, for example, mouthwash, toothpaste and lip balms, has an unpleasant taste. It is responsible for the pungent burning sensation associated with mouthwash and toothpaste, which limits patient acceptance of these products. Other compounds similar to thymol can also produce an unpleasant taste sensation.
The inclusion of compounds that could inhibit, or at least modulate, the unpleasant taste sensation of ingredients like thymol, could improve patient compliance with regimens using medicines or personal hygiene products containing these kinds of active ingredients. Moreover, the inclusion of compounds that could increase aversive tastes of toxic agents that normally have little taste could improve the safety of these products. Therefore, there exists a need in the art for methods that can be used to identify compounds that can modify taste perception in such ways, particularly for compounds such as thymol and similar compounds.